Surface light-emitting apparatuses typically include LEDs secured to a frame. The LEDs are powered by an electric power supply. The surface light-emitting apparatuses are generally used for indoor or outdoor advertisements or signs, and have been developed to be configured such that they can be conveniently installed and have low electrical power consumptions and durability due to their simple structures. Light can be surface-emitted from LEDs during the day as well as at night.
FIG. 1 illustrates a sectional view of a conventional surface light-emitting apparatus 1.
The conventional surface light-emitting apparatus 1 is constructed by manufacturing a framework 10 having a letter or a pattern of a sign or an advertisement, applying a reflective agent 12 with a predetermined agent on an inner surface of the framework 10, disposing a plurality of LEDs 20 whose size and shape are not limited upward, downward, and laterally at an interval of 1 to 5 cm along the framework 10 within the reflective agent so that electric currents can flow to the LEDs 20 through wires, and fixing the LEDs 20 with a primary transparent epoxy resin 30 and a secondary epoxy resin 40 having a color.
After the surface light-emitting apparatus 1 is fixedly attached onto a wall 50 with bolts 52 and one side end of a wire 60 connected to the LEDs 20 is extracted to the outside of the framework 10, electric power is supplied to the wire 60 from a power supply unit 70, so that light can be surface-emitted from an entirety of the surface light-emitting apparatus 1. Accordingly, the surface light-emitting apparatus 1 can act as an effective advertisement.
However, according to the conventional surface light-emitting apparatus 1, a size of an advertisement is limited due to the heavy weights of the primary epoxy resin and the secondary epoxy resin when the advertisement is installed on the wall 50.
That is, the conventional surface light-emitting apparatus 1 requires a considerably large space in order that a coupling device including bolts 52 for fixing a relatively heavy advertisement can firmly support the advertisement. Further, it should have a complex structure, i.e. a large and complex structure for sufficiently supporting a load.
Meanwhile, Korean Patent No. 2002-0365307 titled “Indoor/outdoor Advertising Apparatus and Method for Manufacturing the Same” discloses another surface light-emitting apparatus.
However, the surface light-emitting apparatus is configured by applying a primary transparent epoxy resin with a height of 0.5 to 5 mm on an interior surface of a framework, disposing a plurality of LEDs on the primary transparent epoxy resin such that electric currents can flow to the LEDS, applying a secondary transparent epoxy resin or a transparent epoxy resin mixed with a dispersing agent such that the plurality of LEDs are buried, and applying a tertiary epoxy resin where a semi-transparent fluorescent pigment and a dispersing agent are mixed on the transparent epoxy resin.
Accordingly, the conventional surface light-emitting apparatus is configured such that it requires a separate dispersing layer for uniformly dispersing light emitted from LEDs, i.e. a dispersing agent and primary, secondary, tertiary epoxy resins should be filled on the whole. Thus, the conventional surface light-emitting apparatus also requires a heavy structure, a very complex manufacturing process, and high manufacturing costs.
Therefore, there has been a need for development of a new concept of a surface light-emitting apparatus which allows for a reduction of weight, simplification of a manufacturing process, and a reduction of manufacturing costs as compared with the conventional surface light-emitting apparatus 1.